Current developments within scientific technologies urge product design toward more sophisticated trends. Recently, axiomatic design has been utilized in order to overcome the difficulties of more sophisticated design requirements. The axiomatic design is a design methodology employing two axioms, the independence axiom and the information axiom, and can be applied in diversified fields. This axiomatic design provides the ability to illustrate the correlations among design factors using matrices, and these matrices also show the correct design direction. Thus, applying these axioms in design often corrects design problems, as shown in the coupled design. Through a new approach termed the "Continuous Functional Analysis," fewer Functional Requirements (FRs) can be used along with Design Parameters (DPs) under given constraints. We can present a simple correction method using the level curve, along with the gradient values.